Synthetic resin magnifying glass



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SYNTHETIC RESIN MAGNIFYING GLASS Original Filed Sept. 14, 1935 \d I w.

Patented Mar. 21, 1939 UNITED STATES Search Ream PATENT OFFICE SYNTHETICRESIN MAGNIFYING GLASS Nathan M. Stanley, Dayton, Ohio Originalapplication September 14, 1935, Serial Divided and this applicationtober 23, 1936, Serial No. 107,223

1 Claim.

My invention relates to magnifying lenses.

It is the particular object of my invention to provide a magnifying lensof synthetic materials of such type that it can be moulded and extrudedin final form without the necessity of expensive grinding and polishingoperations ordinarily required in connection with the manu facture ofmagnifying lenses made of glass.

It is an object of my invention to provide a novel form of magnifyinglens of synthetic materials.

It is a further object of my invention to provide a magnifying lens ofsynthetic resin material which, in addition to possessing the advantagesof a lens formed of glass, is lighter in weight, cheaper to manufacture,substantially chip proof, tough, water resistant and stronger thanglass.

It is a further object of my invention to provide such a lens which isof such shape as to secure the ultimate degree of vision of the materialsought to be magnified by the lens.

The surfacing of glass is diflicult and expensive and this operation iseliminated by my invention.

These and other objects and advantages will appear from the followingdescription taken in connection with the drawing.

This application is a division of my application Serial No. 40,595,filed September 14, 1935, which matured into United States LettersPatentNo. 2,086,286, granted July 6, 1937.

In the drawing:

Figure 1 is a perspective view of one form of lens constructed accordingto the principles of my invention;

Figure 2 is a top plan view of a second form of magnifying lensconstructed according to the principles of my invention;

Figure 3 is an elevational view, in section, of the structure shown inFigure 2, taken along the line 3-3 of Figure 2.

While the principles of my invention may be practiced by utilizingvarious types of synthetic plastic resins which possess opticalproperties, it is preferable that those employed be cheaper than glass.A typical resin of this character, which I have employed is water-whiteand as clear as ordinary crown glass. It does not chip nor break whendropped. It is exceedingly tough. It is a synthetic resin of theacrolein type derived from coal tar. It is a thermoplastic resin,readily softening at approximately 248 degrees F. It is capable of beingmachined, turned, curved. and cut, and is possessed of an extremely hightensile strength and high resistance to water. It is unaffected bydilute acids and is resistant to attacks of alkalis and alcohols.Furthermore, it is capable of being cemented. In the trade, in GreatBritain, this resin is known and sold under the trade name of Resin-MnWhile the above described material is preferable in the practice of myinvention, the use of other resins is comprehended by me. For instance,urea-formaldehyde condensation products known under the trade names ofPollopas, Plastopal" and "Shel1an being resins which are clear,transparent and colorless as is glass, are possessed of the desiredoptical and transparent properties.

According to the principles of my invention, the lenses may be formed byextruding or moulding or by turning and forming the material. Whenmoulded, the material emerges from the mould with such high polish thatlittle, if any, additional polishing is necessary. The preliminaryroughing or grinding, preliminary to polishing which is necessary in themanufacture of lenses from glass, is totally obviated.

In Figure 1, one form of magnifying lens, constructed according to theprinciples of my invention, is illustrated. This lens comprises a bodyhaving an arcuate top'surface I, straight side walls 2, straight endwalls 3 and a flat bottom wall 4. The lens is of substantiallongitudinal extent whereby, by its use, an area of substantial lengthmay be magnified. This is extremely desirable in the reading of fineprinted matter. The depth of the body is such that the lens may beplaced directly upon the fine type or other material sought to bemagnified.

The lens illustrated in Figures 2 and 3 is circular, provided with anarcuate topsurface 5, slightly curved substantially cylindrical sidewalls 6 and slightly arcuate bottom surface I. The provision of theslightly arcuate bottom wall 1 makes it possible for the lens to bedirectly supported by the matter sought to be magnified, while theslightly arcuate bottom surface thereof is spaced therefrom, the surfacebeing protected from scratching.

It will be understood that the above described structure is merelyillustrative of the manner in which the principles of my invention maybe utilized and that I desire to comprehend within my invention suchmodifications as come within the scope of the claim and the invention.

Having thus fully described my invention what I claim as new and desireto secure by Letters Patent is:

As a new article of manufacture for use as a radius than said topsurface joining said top magniiying reading lens comprising atranssurface and side walls, straight end walls, and a parent body oi.relatively great length in proflat bottom wall, the depth of the bodybeing such portion to its width provided with an elonthat the lens maybe placed directly upon the gated arcuate top surface, said body havingsurface containing the material to be magnified. 5

straight side walls with curved surfaces of shorter NATHAN M. STANLEY.

